Contact finger



NOV. 11,1924.- 1,514,904

v Y- i A'. G. HENRICKS CONTACT FINGER Fil ed March 18 1921 relatively at ent ow. ll, 1%24.

ARTHUR G. HENRIGKS, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO IPAWLINQ & HAIRCNISCHFEGER COMPANY, OF MILWAUEE, WISCONSIN, A CORPORATION OF WISCONSIN.

CONTACT Application filed March is,- 1921. serial no. team.

To all whom 222 ma concern:

Be it known that ARTHUR G. HENRICKS, a citizen of the United States, residing at Milwaukee, county of Milwaukee, and State 5 of Wisconsin, have invented new and use ful Improvements in Contact Fingers, of which the following is a specification.

This invention relates to electrical switches and is particularly directed to the stationary contacts of such switches, for instance, the contact fingers of controllers.

The primary object of this invention is to provide a pivoted contact finger which is so constructed that the finger barmay be readily removed by manipulating easily accessible parts upon its outer side without disturbing the pivoted portion, and to so organize such mounting that for the purpose of such removal, transverse movements of the finger or of parts of thewmounting are not necessitated whereby either an open or closed pivotal bearing may be used.

Other objects are to provide a contact,

such for example, as the contact finger of controllers, which tho resiliently pressed, will nevertheless be retained in substantially correct position altho the resilient means may break; to provide a contact to finger which will insure good contact and avoid stubbing or binding; which may be cheaply and readily manufactured and applied'to' existing types of controllers and which altho readily removable and accessias ble and capable of heavy duty, nevertheless will have relatively small transverse dimensions so that a series of such contacts may be arranged upon a supporting insulating base with relatively small spacing therebeto tween.'

For the purpose of illustrating anembodiment o the invention, a contact finger for a drum controller has been shown the drawings, in which:

Fig. 1 is a side elevation of a contact finger artly in section showing in dotted lines t e contour of the co-operating con troller drum.

Fig. 2 is a section on, the line 22 of 5c Fig. 1 with the insulating base removed The contact fin er comprises a bar or body'portion 1 w ichv may be formed of sheet brass withthe longitudinal edges upflanges adjacent t portion of such support, the screw turned to give the requisite stiifness by provlding a substantially channel section. This body portion carries at its outer end a contact proper 2 which is adapted to make slldlngcontact with the movable contacts cargied upon the controller drum indicated at A supporting "portion is provided which may be of copper and is formed with upturned ears 4 which carry a-pintle 5, such pintle being convenientl retained in position by split pins 6. Tivotally mounted upon the pintle is a block 7 of metal which is rectangular in outline and has a widened lower portion 8 which loosely engages the inner surfaces of the upturned ears 4 of the support. This block passes thru a rectangular opening formed .in the bottom orwith a hole 10 whose lower surface is substantially in line with the. upper surface of the bottom portion 9 of the contact finger when ,in normal position. passed thru this hole and serves to retain the contact finger upon the block 9, such pin having an upturned substantially right angle portion 12 which forms a convenient manipulating handle.

To prbvide additional bearin contact between the body portion and the look 7 such body portion mayhave downwardly turned which the block asses. The support has an upwardly exten ing forward arm 13 which is provided with an outwardly projecting portion 145, The rear portion .0 the sup port has a downwardly extending portion 15 to which an electrical lead 16 is secured by means of a screw 17. The support is conveniently held in position upon an insulating base 18 by means of screws-19 and 20 which passthru tapped holes in the bottom tendingupwardly a slight distance above such support asindicated at 21.

y The contact=finger is placed in intimate electrical contact with the lead 16 by means of a relatively large, flexible, braided conductor 22 which has at one end a terminal 23 secured beneath the screw 17 and in engagement with the lead 16, and at its other Apinllise sides of the opening thru iefex- 1 end a terminal 23 which is riveted the rear 1 J or projection 14 of the support.

end of the contact finger, such rivet forming an enlar ed projection 24 extending a slight distance low the under side of. the contact finger. A s ring 25 is positioned between the rear en of the contact finger and the support and is retained in fposition by means of the projecting end 21 o the screw 19 and the projecting portion 24 of the rivet.

To prevent excessive inward motion of the contact an adjusting screw 26 is threaded thru the contact finger and engages the top The upper end of the screw is provided with a square head 27 which co-operates with the upturned lip 28 of a spring 29 to prevent accidental rotation of the screw. 1

The positioning of the pin 11 with its right angle arm 12 in close proximity to the terminal portion 24 allows such pin and terminal to co-operate-to prevent accidental withdrawal of the pin, for when the pin is slid rearwardly the base of the right angle portion 12 engages the terminal 24 and revents further movement of such pin. owever, when it is desired to remove the pin, the rear portion of the contact finger is depressed against the action of the spring 25 and the pin is then withdrawn, passing over or rounded faces of y or being the terminal portion 24 of the conductor. The contact finger may then be slipped outwardly from off the rectangular member 7 It will thus be seen that a contact finger has been provided which may be quickly and readily removed by the manipulation of means which are readily accessible from the outer side of the contact finger. It will also be seen that inadvertent or accidental disengagement of the contact finger and support is prevented and such finger is securely retained in operative position except when such detachment is voluntarily made.

Stubbing or binding is avoided by having.

the under surface of the contact 2 and the pivot 5 substantially in line with a tangent from the upper surface of the controller drum, so that the contact may readily ride over the co-operating segments of the drum, 1t being understoodthat the usual beveled the contact 2 are provided.

It will also be seen that these contact fingprs may be placed in close proximity to eac other when it is desired to closely assemble a'series of fingers upon a controller for instance, and that the removal of any one finger does not necessitate a lateral motion of any of the connecting members thereby minimizing the necessary lateral clearance. Also, if the sprin should break, the fingerls'still revented rom damaging other portions 0 thecontroller as it is so retained that it is 1pgevented from either falling off ocked off its support and also prevented from having sidewise swinging motion by the rectangular contour of the member 7 together with the corresponding co-operating rectangular opening in the contact finger.

I claim:

1. In an electric switch having movable and stationary contacts, the combination of a contact finger having a body portion, a contact carried at one end thereof, a spring resiliently bearing upon'the other end thereof, and intermediate pivotal: ly mounted means detachably joined to said contact finger, and adapted to be discon nected from the'exterior side to allow the finger to be removed without disturbing the pivotal connection. I

2. A contact finger comprising a body portion, a contact carried at one end thereof, a support, a member pivotally mounted upon said support and having slip joint connection on the exterior side with said contact finger, and a spring positioned between said support and sai contact finger.

3. In a device of the character described, the combination of a support, an intermediate member pivotally connected with said support, a contact finger provided with an aperture receiving a portion of said inter- .mediate member, and a slidable key on the thru said body portion, an exteriorly accessible pin for detachably securing said member to said body portion, anda spring positioned between said body portion and said support.

5. The combination with a support and connecting member pivoted to the support, a contactfinger adapted to be loosely engaged by the connecting member, and a quick detachable connection between. said member and the finger, adapted tobe manually manipulated from the exterior.

6. The combination with a support, of a connecting member having closed pivotal connection with the support, a contact finger having an apertnne through which the cobnecting member passes, a quick detachable member adapted to engage the connecting member and contact finger to normally prevent disengagement of the finger from the connecting member, and means for subjectingsaid quick detachable member to .resilient pressure to prevent accidental disengagement thereof.

'7.:A contact finger comprising ,a body portion, a support mounted below said body portion, a member pivotally secured to said A tion, and means upon the outer side 'of'said body portion for detachably. joining said body portion to said member,

8. A contact finger comprising a body portion, a contactpositioned at one end thereof, resilient means acting upon the other end thereof, a. support mounted adjacent said body portion, a member passing thru said body portion and pivotally joined to said support, a pin passing thru said member and engaging th upper face of said body portion, and a conductor electrically connecting said support and the last mentioned end of said body portion and having a terminal portion positioned adjacent one end of said pin whereby said pin is normally held in position by said terminal.

9. A contact finger comprising a body portion, a support therefor, means including a pin for retaining said contact finger in operative engagement witlrsaid support, and a flexible conductor electrically joining said body portion and said support and having a terminal co-operating with said pin to retain said pin in operatlve position.

10. A contact finger comprising a support, a member pivotally mounted thereon, a body portion having at its forward end a contact, and provided with an opening thru which said pivotally mounted meming a terminal portion co-operating with said pin to retain said pin in operative position, and a securing means passing tln'u said terminal and the rear end of said con tact finger and engaging said spring to re tain said spring in position.

11. In an electrical switch, the combination of an insulating base, a support mounted thereon, a screw passing thru said insulating base and support and retaining said support upon said base, said screw projecting above the upper surface of said base, a contact finger pivotally mounted upon saidv support, a conductor electrically joining said support and said finger, a rivet securing said conductor to said finger and havin a ortion ro'ectin below said fin b 2: D

er, and a spring positioned between said support and said finger and retained 111 position by said screw and said rivet.

ARTHUR G. HEN RN 1 KS. 

